Sleep patterns share common pathways with nociceptive stimuli. Several important factors are reviewed in considering connections between sleep and pain. Causes for sleep fragmentation include sleep disordered breathing; abnormal leg movements, including restless legs syndrome and periodic limb movements; and underlying mood disorder, which may be exacerbated by physical symptoms. Identification and management of insomnia includes the definition of the condition, pharmacologic interventions, the role of circadian rhythms and clock adjustments, and the use of cognitive behavior therapy for insomnia.